On Fri, Feb 18, 2022 at 7:57 AM Rob Clark <robdclark@xxxxxxxxx> wrote: > > From: Rob Clark <robdclark@xxxxxxxxxxxx> > > With native userspace drivers in guest, a lot of GEM objects need to be > neither shared nor mappable. And in fact making everything mappable > and/or sharable results in unreasonably high fd usage in host VMM. > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> > --- > This is for a thing I'm working on, a new virtgpu context type that > allows for running native userspace driver in the guest, with a > thin shim in the host VMM. In this case, the guest has a lot of > GEM buffer objects which need to be neither shared nor mappable. > > Alternative idea is to just drop the restriction that blob_flags > be non-zero. I'm ok with either approach. Dropping the restriction sounds better to me. What is the use case for such a resource? Does the host need to know such a resource exists? > > drivers/gpu/drm/virtio/virtgpu_ioctl.c | 7 ++++++- > include/uapi/drm/virtgpu_drm.h | 1 + > 2 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > index 69f1952f3144..92e1ba6b8078 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c > +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c > @@ -36,7 +36,8 @@ > > #define VIRTGPU_BLOB_FLAG_USE_MASK (VIRTGPU_BLOB_FLAG_USE_MAPPABLE | \ > VIRTGPU_BLOB_FLAG_USE_SHAREABLE | \ > - VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE) > + VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE | \ > + VIRTGPU_BLOB_FLAG_USE_INTERNAL) > > static int virtio_gpu_fence_event_create(struct drm_device *dev, > struct drm_file *file, > @@ -662,6 +663,10 @@ static int verify_blob(struct virtio_gpu_device *vgdev, > params->size = rc_blob->size; > params->blob = true; > params->blob_flags = rc_blob->blob_flags; > + > + /* USE_INTERNAL is local to guest kernel, don't past to host: */ > + params->blob_flags &= ~VIRTGPU_BLOB_FLAG_USE_INTERNAL; > + > return 0; > } > > diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h > index 0512fde5e697..62b7483e5c60 100644 > --- a/include/uapi/drm/virtgpu_drm.h > +++ b/include/uapi/drm/virtgpu_drm.h > @@ -163,6 +163,7 @@ struct drm_virtgpu_resource_create_blob { > #define VIRTGPU_BLOB_FLAG_USE_MAPPABLE 0x0001 > #define VIRTGPU_BLOB_FLAG_USE_SHAREABLE 0x0002 > #define VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE 0x0004 > +#define VIRTGPU_BLOB_FLAG_USE_INTERNAL 0x0008 /* not-mappable, not-shareable */ > /* zero is invalid blob_mem */ > __u32 blob_mem; > __u32 blob_flags; > -- > 2.34.1 > _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization